The invention relates to a heat exchanger having a set of pipes, with the heat exchanger pipes being arranged horizontally for heating a flowing medium with steam.
Heat exchangers having a set of pipes are known in which the heating medium contained in the pipes is guided partially in crossflow and partially in unidirectional and counterflow to the medium to be heated. In such heat exchangers relatively large differences in temperature between the heating medium and the medium to be heated occur at individual points on the heat exchanger. In certain applications (for instance, in the use of such heat exchangers for boiling wort in beer production) this can lead to disadvantages in that as a result of the excessive temperature difference incrustations and deposits are produced in the heat exchanger which considerably impair the heat transfer and require costly maintenance work.
The state of the art also includes double pipe heat exchangers in which the heating medium and the medium to be heated are led in counterflow to each other. In order to achieve a sufficient surface area of the heat exchanger it is known in this case for a plurality of parts of the heat exchanger connected to each other by deflectors to be connected in series. However, when steam is used as the heating medium such heat exchangers have the considerable disadvantage that the condensate produced when the steam is cooled must in practice be forced through the whole heat exchanger to the steam outlet end which results in considerable impairment of the heat transfer.